顶空气相色谱法测定河蟹中三甲胺的含量

Determination of trimethylamine in Chinese mitten-handed crab by headspace gas chromatographic method

采用顶空气相色谱法，对河蟹腿肉中的三甲胺含量进行测定，并探索了NaOH加入量、样品平衡温度、超声波处理时间对三甲胺含量测定的影响。结果表明：NaOH加入量为2．00g、样品平衡温度为40℃、超声波处理时间为10min时，蟹腿肉中的三甲胺可得到充分释放且灵敏度较高。并且测得峰面积与三甲胺浓度在0-25mg／L范围内呈良好的线性关系（R^2=0.9994，n=8），相对标准偏差为0.91％，平均回收率为97.02％，检测限为0.2mg／L。该方法操作简单快速、准确性好，为评价河蟹新鲜程度提供了一种灵敏高效的测定方法.

The trimethylamine（TMA）in Chinese mitten-handed crab leg meat was determined by the headspace gas chromatographic method and searched for the effects of NaOH dosage, equilibrium temperature, treatment time of ultrasonic on the measurement of TMA, The result showed that NaOH dosage 2.00g, equilibrium temperature 40℃, treatment time of ultrasonic 10min,TMA in crab leg meat could be released adequately and the sensitivity was relatively high. The linear range between the peak area and the concentration of TMA was 0-25mg/L （ R^2 = 0.9994, n = 8）. The relative standard deviation was 0.91 % with the average recovery ratio of 97.02% and the detection limit of TMA was 0.2mg/L. This method was simple, rapid and accurate and it provided a sensitive and efficient method for assessing the freshness of crab.